The research proposed for the next year can be subdivided into three parts. a) Nucleohistones. The preparation of chromatin and its characterization by FTIR has been accomplished. In order to complete this section of the project our samples need to be cleaned of fluorescent impurities in order to obtain high quality Raman spectra. b) Poly-L-arginine/DNA complexes. We propose to prepare NDA/(Arg)n complexes at sufficient concentrations for Raman and FTIR studies by the methods developed in the study of DNA/(Lys)n. Complete characterization of solutions and films by vibrational spectroscopy should allow an informative comparison with the results of the DNA/(Lys)n system. c) Purified histone components/DNA complexes. We propose the isolation and purification of the various histone subfractions by chromatographic procedures described in the literature. A careful study by Raman and infrared spectroscopy should allow us to draw some conclusions regarding the secondary structure of these materials. We would then reconstitute various histone/DNA complexes and characterize them by Raman and FTIR spectroscopy, particularly dichroism studies of oriented samples, in order to obtain comparative information concerning the structure of the complex and the nature of the molecular interactions.